Cut-out for arc lamps



(No Model.)

D. HIGHAM. GUT-OUT FOR ARC LAMPS.

P10541753. Patented Oct. 8, 1 895.

JJ/ATTOR EYJ ANDREW UYGRANAMPHOTO-LH'HQWASHINGTONJC.

UNITED STATES PATENT OFFICE.

DANIEL HIGI-IAM, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE I-IIGI-IAMELECTRIC COMPANY, OF PORTLAND, MAINE.

CUT-OUT FOR ARC LAMPS.

SPECIFICATION forming part of Letters Patent No. 547,753, dated October8, 1895.

Application filed June 27, 1895- Serial No. 554i (N0 model-3 To all whomit may concern:

Be it known that I, DANIEL HIGHAM, a citizen of the United States, and aresident of Boston, Suffolk county, Massachusetts, have inventedImproved Out-Outs for Are Lamps, of which the following is aspecification.

This invention relates more particularly to constant-potential arclamps; and its object is to produce an effective automatic cut-out forsuch lamps without any liability of it binding or holding the carbon-rodduring normal working of thelamp, as more fully shown and describedhereinafter.

In the accompanying drawings, Figure 1 is a diagram of a simple form ofclutch'arc lamp provided with my invention, and Figs. 2 and 3 arediagrams illustrating the action of my invention.

In Fig. 1, A represents the upper carbon carried by a movable rod A,while B is the lower or fixed carbon. Acting upon the movable carbon-rodA is a clutch D, one end of which touches upon a stop d on the frame,while the other end is connected through a link cl to a lever L, pivotedat Z. Wire windings S in a shunt-circuit around the arc act magneticallyupon a solenoid-core Z, supported by leverL. Coarse-wire windings in themain circuit also act magnetically upon solenoid-core Z in opposition tothe windings S.

Q is a spring to act upon the lever L against the magnetic action of theseries windings C, while B is a stop on the frame to limit the movementof the lever L.

In the carbon-rod A is a groove W to engage with a pawl 15, actuated byits own gravity, when the carbon-rod is fully fed down, to tip a leverM, pivoted on the frame at K, and pull a contact-piece m, which iscarried by the lever, from between contact-springs n and n. These latterare connected in the circuit of the shunt-windings S and are carried by,but insulated from, the frame by insulating-blocks P and P. Thecontact-piece m is insulated from the lever M by insulation-plates o andQ).

U is a stop on the frame to limit the movement of lever M, while 4 is apawl upon the lever to engage with the groove Win the rod A when thelatter is raised upward, and so cause the lever M to tilt over fromposition Fig. 2 to position Fig. 3 to close contact of piece on withsprings n and n. Thecircuits between the terminals X Y of the lamp areindicated by arrow-heads.

It will be seen from Fig. 1 that as the carbon-rod A is fed down thegroove W will not engage with the pawl 1", but pass the same and engagewhen the rod A is fed down sufficiently with the pawl 2?, whereby thecarbonrod will pull out the contact-piece m from between thecontact-springs n and n, and the lever M will tip downward on the pawlend, which should be slightly heavier than the end having thecontact-piece m and rest upon stop U, as shown in Fig. 2, in whichposition the shunt-circuit will be held open and the carbon-rod can beraised up by the series windings 0 (not being opposed by the magneticeffect of the shunt-windings S) as far as the limited movement of themechanism would raise it without closing the shunt-circuit, as will bereadily understood. When the carbon-rod is raised up by hand, however,to put in a new set of carbons, for instance, it will be seen that thegroove W will engage with the pawl r and tip over the lever M to forcethe contact-piece m between the contactsprings n and n,in which positionthe springs n and n will hold the lever M during the normal working ofthe lamp, as shown in Fig.1.

Fig. 3 will serve to show how the pawl 0 will be disengaged from thegroove W after the lever MI is tipped over sufficiently to close theshunt-circuit, in order to allow the carbon-rod to be pushed fully up.It will be seen that the pawl 1' will bear or strike on the lever M ate, whereas the pointf of the pawl r will follow the circle indicated bythe dotted line, and consequently draw out of the groove W, as shown, toallow the carbon-rod to pass up, as will also be readily understood.

It will be seen that during the normal working of the lamp there will beno possible chance of this cut-out binding or holding the carbon-rod, asthere is nothing to bear against 5 the carbon-rod but the delicatepressure of the pawls r and t, and they are so pivoted to the lever Mthat they can in no way lock or wedge the rod. It will also be seen thatby the use of the groove W the carbon-rod can [00 be round incross-section, inasmuch as the groove wlll engage with the pawls r andif, no

sar /5s matter to what position the rod might be when the rod is pushedup by hand to close turned. the circuit of said shunt windings, substan-I claim as my inventiontiaily as described. An electric arc lampprovided with suitable In testimony whereof I have signed my 5 feedingmechanism having shunt windings, name to this specification in thepresence of 15 in combination with a carbon rod having a two subscribingWitnesses.

groove, a lever having a pawl to engage with DANIEL HIGHAM. said groovewhen the carbon rod is fed down iVitnesses: and open the circuit of saidshunt windings, E. A. WOODBURY,

IO and a second pawl to engage with said groove A. N. BONNEY.

